fixes nim-lang#12453 (nim-lang#12475)

doc/manual.rst

@@ -5100,6 +5100,25 @@ The problem here is that the compiler already decided that ``something()`` as
 an iterator is not callable in this context before ``toSeq`` gets its
 chance to convert it into a sequence.
 
+It is also not possible to use fully qualified identifiers with module
+symbol in method call syntax. The order in which the dot operator
+binds to symbols prohibits this.
+
+.. code-block:: nim
+    :test: "nim c $1"
+    :status: 1
+
+   import sequtils
+
+   var myItems = @[1,3,3,7]
+   let N1 = count(myItems, 3) # OK
+   let N2 = sequtils.count(myItems, 3) # fully qualified, OK
+   let N3 = myItems.count(3) # OK
+   let N4 = myItems.sequtils.count(3) # illegal, `myItems.sequtils` can't be resolved
+
+This means that when for some reason a procedure needs a
+disambiguation through the module name, the call needs to be
+written in function call syntax.
 
 Macros
 ======